Working mixer. Yay!

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@111 84d2e878-0bd5-11dd-ad15-13eda11d74c5

1 files changed, 14 insertions, 7 deletions

diff --git a/src/audio.c b/src/audio.c
index 5ac4b13..8bb95fa 100644
--- a/src/audio.c
+++ b/src/audio.c
@@ -18,21 +18,28 @@
 
 #include "types.h"
 
-static void audio_mix(void *data, Uint8 *stream, int len) {
+static void audio_mix(void *data, Uint8 *stream8, int len) {
 
 	AudioContext *a = data;
-	int i;
+	int i, j;
 	Uint32 amount;
-	size_t j;
+	Sint16 *stream = (Sint16 *)stream8;
+	
+	len /= 2;	/* Samples */
 	
+	/* Zero the buffer */
 	for ( j=0; j<len; j++ ) {
 		stream[j] = 0;
 	}
 	
+	/* For each currently playing sound... */
 	for ( i=0; i<AUDIO_MAX_SOUNDS; i++ ) {
 		
+		/* Playing? */
 		if ( !a->sounds[i].inuse ) continue;
-		amount = (a->sounds[i].dlen - a->sounds[i].dpos);
+		
+		/* Calculate how many samples to mix */
+		amount = a->sounds[i].dlen - a->sounds[i].dpos;
 		
 		if ( amount > len ) {
 			/* The sound remaining in this channel more than fills the buffer */
@@ -40,7 +47,7 @@ static void audio_mix(void *data, Uint8 *stream, int len) {
 		}
 		
 		for ( j=0; j<amount; j++ ) {
-			float samp = a->sounds[i].data[a->sounds[i].dpos + j];
+			Sint16 samp = a->sounds[i].data[a->sounds[i].dpos + j];
 			stream[j] += samp * a->sounds[i].volume;
 		}
 		
@@ -92,8 +99,8 @@ void audio_play(AudioContext *a, char *file, float volume, int repeat) {
 	
 	/* Put the sound data in the slot */
 	SDL_LockAudio();
-	a->sounds[idx].data = (Uint16 *)cvt.buf;
-	a->sounds[idx].dlen = cvt.len_cvt;
+	a->sounds[idx].data = (Sint16 *)cvt.buf;
+	a->sounds[idx].dlen = cvt.len_cvt / 2;
 	a->sounds[idx].dpos = 0;
 	a->sounds[idx].inuse = 1;
 	a->sounds[idx].repeat = repeat;